GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Didital Things
In the Thread: The BSO and Digital Music.

Post Subject: Putting the picture together.Posted by Romy the Cat on: 4/23/2009

manisandher wrote:
"A little information is dangerous. I find it incredible that people with absolutely no understanding about the technology and its application feel the need to speak with the authority of an expert. The HDCD processes "Peak Extension" and "Low Level Extension" are only available when creating 44.1kHz/16 bit material. These processes are user selectable and were not used in the creation of the BSO Classics masters. Further, we have not made a master in our history that utilized any process that requires decoding to be played back correctly. Period. At 88.2 kHz the HDCD process alerts the PMI filter chip in the DA converter that the material was created with an AD converter with a known anti-aliasing filter and noise shaping curve. The PMI filter chip can then utilize a reconstruction filter optimized for the specific AD converter used for the creation of the master. This process is invisible to all other DA converters and the HDCD dither/noise shaping is considered to be the dither of choice for high resolution material."

I do not think that anyone contest Mark’s position of authority of an expert and I no idea why he feel a need to be defensive. What we do is trying to reconstruct from bits and pleases of information some facts about the mastering process of the BSO recording and in a way of doing to learn something. They were Mark’s words: “you will actually get improved audio if your DA converter properly decodes the HDCD (Even at 88.2 kHz /24 bit!)” that were misleading as he referred initially to “decoding HDCD” not to just using HDCD marks to throw a DAC to engage the “anti-aliasing filter and noise shaping curve”. From he said initially I was under impression that BSO file are HDCD encoded that I found ridicules to do under 88/24.

There was second factor that I found worth to note. Experimenting with Low Level Extension in past (all on 16 bit) I did found that Low Level Extension (or actually a mild Pacific’s proprietary compression) had a positive effect and was very much align with some of my critic of the BSO files. I am not exactly calling the BSO file as “intelligently uncompressed” but there is something in me feels that suggest me to do so. The BSO files are in a way as an un-groomed dog where dymick in a way obliterates the fine satellites of imaging. I thought that with “intelligent compression” that might be addressed. With FM files I have not an “intelligent compression” but over compression and dynamically the raw 88/24 files and not even close to FM result. However, from imaging position FM results are very much contestable and in some way more interesting. Do not forget that the 88/24 files and the FM files were most likely made from the very same feed.

I am writing it and it ridicules that I put myself in a position where it sounds like I am trying to solicit Mr.Donahue… to “properly” compress his files. I certainly do not do it and I certainly do not imply that I know how they need to be compressed. But I would also point out that from a certain perspective I do not consider the BSO files as “as good as they could be” and I did comment about some of my dissatisfaction in imagine department. A hint might be in the fact that Deutsch Requiem is better than other files), what different between them only Mark Donahue knows.

Finally, I am not specializing in mastering of recordings or about the evaluation of technologies to do so but rather in listed and discriminating the results. What I see in this exchange is that Mark unwillingly agrees with my observations. He said “If you can turn off the HDCD decoding you will find a significant decrease in the spatial imaging and overall imaging acuity” but it look like exactly how we, the people with no HDCD processors, hear the BSO files.

I think instead of blaming me in impersonisation of authority while have little knowledge Mr. Donahue might use his considerable knowledge and to make our BSO recordings to play via the HDCD-disabled processors without the “significant decrease in the spatial imaging and overall imaging acuity”. We are in away all rowing in a same boat and have the same objectives – to make BSO sound file as good as they could be. The relying on HDCD to engaged specific filters I think is not kosher way to do as the unfortunately there is not a lot of DACs with Pacific decoding chips out there and even those that can recognize HDCD and have on-board the complex interpolation HDCD decoding filter are not necessary the worthy performers otherwise. This conversation encourages me to rewire my Pacific and to try using it’s D/A for paying the BSO files. Nowadays one of my Melquiades out of service but when I will be back and when my installation will be up then most likely I will try to do it.

Rgs, Romy the Cat

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